Update TODO comment with correction

[hensha256]

Did a gas test to check which is cheaper between sending the WETH to the Pair at the time you wrap, or in the V2 payment. Transferring at the time of V2 function is cheapest.

You cannot wrap WETH into a specified recipient address so in either scenario it always has to go

• user -eth-> router
• router wraps eth into weth INTO ROUTER
• router -weth-> pair

the only change is when the weth is sent to the pair, and this is the cheapest.

I think this is because transferring the WETH at the time of wrapping increases the number of non-0 calldata bytes dramatically.